The objective of this research project is to determine the role of viruses and interferon in immunologic and immunopathologic processes. The observation that interferon is produced by lymphocytes as an integral part of the immune response and can regulate immunity suggested that interferon might be produced in certain autoimmune disorders. We found immune interferon in sera of patients with active immunologic diseases such as systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's Syndrome and vasculitis. The presence of interferon in immunologically-mediated diseases appears to be limited to only certain collagen-vascular diseases since we did not detect interferon in a variety of other diseases. Earlier studies demonstrated that virus-induced interferon can enhance IgE mediated histamine release (immediate hypersensitivity). We have recently found that interferon can also augment basophil chemotaxis. These studies suggest that viruses and interferon may be involved in the pathogenesis of allergic reactions.